# TD Agent Utility – Checkpoint Save (Website & Deployment Verification)

> TD Agent Utility – Checkpoint Save (Website & Deployment Verification) is a paid API for AI agents from tdagentutility.co.uk, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-16).

Saves a verification checkpoint for a website or deployment, storing the result of HTTP, DNS, TLS, and Chromium screenshot checks for later retrieval.

## Facts

- Endpoint: POST https://tdagentutility.co.uk/v1/checkpoint-save?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/td-agent-utility-checkpoint-save-website-deployment-verification-28be0176
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WDO8fQ6roPURvrC3L28Hl

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability td-agent-utility-checkpoint-save-website-deployment-verification-28be0176 -d '<json body>'
```

Example prompt: Save a verification checkpoint for https://myapp.example.com — I just ran a deployment and want to record that the site passed HTTP, DNS, and TLS checks so I can reference this evidence later.

## When to prefer this

Use this endpoint when you need to durably persist the result of a website or deployment verification check — particularly when you need a tamper-evident, timestamped record (with expiry) that you can retrieve or share later. Prefer this over in-memory or ephemeral logging when auditability, compliance evidence, or cross-session retrieval of verification state is required.

## Known failure modes

- Missing or invalid target URL returns a validation error
- Expired or invalid payment results in a 402 Payment Required response
- Storage backend unavailable causes a 503 error
- Malformed request body returns a 400 Bad Request
- Checkpoint key collision may cause an update rather than a new create

## How this service works

Independent website and deployment verification for AI agents: HTTP, DNS, TLS and Chromium screenshot evidence. Three deterministic tools, x402 V2 Base USDC.

## Output

Returns a JSON object containing a unique checkpoint key, the tool identifier ('checkpoint_save'), a version number, a result status (e.g. 'PASS'), timestamps for creation, update, and expiry, the size of the stored data in bytes, and any warnings generated during the save operation.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "key": "",
  "tool": "checkpoint_save",
  "version": 0,
  "warnings": [],
  "checked_at": "2026-10-15T00:00:00Z",
  "created_at": 0,
  "expires_at": 0,
  "size_bytes": 0,
  "updated_at": 0,
  "result_status": "PASS"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/td-agent-utility-checkpoint-save-website-deployment-verification-28be0176/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tdagentutility.co.uk](https://www.zero.xyz/host/tdagentutility.co.uk/llms.txt)